IL6 and COVID-19: Of the 39 biomarkers of interest, 11 biomarkers showed an overall significant difference in median baseline biomarker levels based on hospitalization and COVID-19 severity up to day 28, including CRP, ferritin, IFNα, IL6, IL8, IL1RA, IP10, MCP1, RANTES, suPAR, and lymphocytes (Figure 1).